# 9.9
class Car:
    """一次模拟汽车的简单尝试"""
def __init__(self, make, model, year):
    """初始化描述汽车的属性"""
    self.make = make
    self.model = model
    self.year = year
    self.odometer_reading = 0

def get_descriptive_name(self):
    """返回整洁的描述性名称"""
    long_name = f"{self.year} {self.make} {self.model}"
    return long_name.title()

def read_odometer(self):
    """打印一条指出汽车里程的消息"""
    print(f"This car has {self.odometer_reading} miles on it.")

def update_odometer(self, mileage):
    """将里程表读数设置为指定的值"""
    if mileage >= self.odometer_reading:
        self.odometer_reading = mileage
    else:
        print("You can't roll back an odometer!")

def increment_odometer(self, miles):
    """将里程表读数增加指定的量"""
    self.odometer_reading += miles


class Battery:
    """一次模拟电动汽车电池的简单尝试"""
    def __init__(self, battery_size=40):
        """初始化电池的属性"""
        self.battery_size = battery_size

    def describe_battery(self):
        """打印一条描述电池容量的消息"""
        print(f"This car has a {self.battery_size}-kWh battery.")

    def get_range(self):
        """打印一条消息，指出电池的续航里程"""
        if self.battery_size == 40:
            range = 150
        elif self.battery_size == 65:
            range = 225
        
        print(f"This car can go about {range} miles on a full charge.")

    def upgrade_battery(self):
        if self.battery_size == 40:
            self.battery_size = 65
            print("Upgraded the battery to 65 kWh.")
        else:
            print("The battery is already upgraded.")

class ElectricCar(Car):
    """电动汽车的独到之处"""

    def __init__(self,make,model,year):
        super().__init__()
        self.battery = Battery()

print('upgrade the battery:')
my_leaf = ElectricCar('nissan','leaf',2024)
my_leaf.battery.get_range()

print("\nUpgrade the battery again:")
my_leaf.battery.upgrade_battery()
my_leaf.battery.get_range()